I've got a 3550 connected directly to a 2610, a 2611 and many PC servers. The routers direct traffic from two different ISP's to my servers. The servers each have a default route to one of the routers, and each router NATs the internal addresses to the appropriate ISP's public IPs.
The servers provide streaming data to the logged in users via consistent TCP connections, i.e. these are not WWW servers which have many opening and closing connections. These are proprietary servers that have a constant connection via a single TCP port to any particular user until that user logs off. The traffic to any given user may not be as constant as an FTP transfer, but it is steady.
Lately we're seeing a lot more "lost" connections, and I suspect the switch-router links because those port LEDs are flashing alternating green-amber which, according to the switch's manual, is an indication of a "Link fault", i.e excessive collisions, CRC errors, etc.
Here is some of the pertinent info:
3550# show run
interface FastEthernet0/32
switchport access vlan 2
switchport mode access
no ip address
duplex half
speed 10
spanning-tree portfast
interface FastEthernet0/48
switchport access vlan 2
switchport mode access
no ip address
spanning-tree portfast
!
interface Vlan2
ip address 192.168.2.1 255.255.255.0
3550# show int f0/32
FastEthernet0/32 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 000c.3018.1da0 (bia 000c.3018.1da0)
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 2/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 10Mb/s
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:54, output 00:00:00, output hang never
Last clearing of "show interface" counters 01:17:11
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue :0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 105000 bits/sec, 49 packets/sec
560233 packets input, 39244907 bytes, 0 no buffer
Received 1087 broadcasts, 16044 runts, 0 giants, 0 throttles
16044 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 1087 multicast, 0 pause input
0 input packets with dribble condition detected
709506 packets output, 186026478 bytes, 57 underruns
0 output errors, 11040 collisions, 0 interface resets
0 babbles, 0 late collision, 9401 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
57 output buffer failures, 0 output buffers swapped out
2610# sh run
interface Ethernet0/0
description Connected to Aspen LAN
ip address 192.168.2.2 255.255.255.0
no ip directed-broadcast
ip nat inside
!
2610#sh int e0/0
Ethernet0/0 is up, line protocol is up
Hardware is AmdP2, address is 0003.6b7d.d1e0 (bia 0003.6b7d.d1e0)
Description: Connected to Aspen LAN
Internet address is 192.168.2.2/24
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 3/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 01:18:05
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 128000 bits/sec, 71 packets/sec
5 minute output rate 34000 bits/sec, 70 packets/sec
709291 packets input, 183629749 bytes, 0 no buffer
Received 1957 broadcasts, 0 runts, 0 giants, 0 throttles
290 input errors, 0 CRC, 0 frame, 0 overrun, 290 ignored
0 input packets with dribble condition detected
564230 packets output, 34548558 bytes, 0 underruns
0 output errors, 16110 collisions, 0 interface resets
0 babbles, 0 late collision, 18958 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
As you can see, this info is about 1:20 after clearing the interface counters. Prior to that, I had "25351 underruns" and "25351 output buffer failures" on the 3550, which was several weeks worth of data. In the 15 minutes of composing this message, the underruns have not increased.
I'm also concerned about the 3550's 5 minute input rate "0 bits/sec, 0 packets/sec". This link is never supposed to be not receiving data, especially since the 2610 shows "5 minute output rate 34000 bits/sec, 70 packets/sec" at essentially the same time.
The 2610 and 2611 are not 10/100 capable, so they are permanently 10/half. There do not seem to be any speed/duplex conflicts, but the speeds indicated are far below the 10Mbps threshold, and are ususally less than 1Mbps.
Are there any obvious errors with my config?
Can some one tell me why there are/were so many 3550 underruns?
I'm wondering if the 3550 is overwhelming the two routers or their links, and would a new 26xxXM relieve the symptoms.
Any other help appreciated.
Tim
